EXERCISE
1. What tools are used in tillage?
2. How should a poor and shallow soil be treated?
3. Why should a poor and shallow soil be well compacted before sowing the crop?
4. Explain the value of a circulation of air in the soil.
5. What causes iron to rust?
6. Why is a two-horse turning-plow better than a one-horse plow?
7. Where will clods do the least harm—on top of the soil or below the surface?
8. Do plant roots penetrate clods?
9. Are earthworms a benefit or an injury to the soil?